This invention is generally directed to a coagulation timer device for monitoring the bleeding time of a patient by administering an incision through the skin and then blotting the blood at predetermined intervals to determine the amount to time necessary for the patient to achieve clotting. More particularly, this invention is directed to a coagulation timer device which minimizes the risk of contact of the patient's blood by a medical technician or person who is monitoring the clotting time.
Before a patient undergoes surgery, a surgeon needs to know the amount of time that is needed for the patient's blood to clot so as to minimize possible problems which could occur during and after surgery. Coagulation timers are commonly used to measure the clotting time of a patient.
One example of a known prior art coagulation timer is a disc-shaped piece of blotter paper. To measure the clotting time, a controlled or predetermined incision is made on the inside of the forearm of a patient, approximately five centimeters below the antecubital crease. Devices for making such a controlled incision are known in the art, two examples of which can be found is U.S. Pat. Nos. 4,078,552 and 4,735,203. A timer is started to measure the amount of time for clotting. At prescribed intervals the medical technician touches the disc-shaped piece of paper to the blood which results from the incision and wicks the blood. The disc is rotated and the technician, after a predetermined amount of time, touches an unadulterated portion of the disc to the blood and wicks the blood. The disc is again rotated and the procedure is repeated until the blood no longer stains the blotter paper. After the bleeding has stopped, the timer is shut off. The bleeding time is the amount from when the timer was started to when it was shut off.
One problem with this type of coagulation timer is that the technician who administers the test risks contact with the patient's blood since the blood is left exposed during the test. Another known prior art coagulation timer has the disc housed within a bag. The bag is torn open to expose a portion of the disc. After each time the blood is wicked, the stained portion of the disc is rotated by the technician into the bag.
While this second type of coagulation timer reduces somewhat the risk of contact with the patient's blood, a possibility still exists that the technician may come into contact with the blood. More specifically, when the disc is grasped to be rotated, the technician could inadvertently grasp a stained portion of the disc. Also, the stained portion can come into contact with the edge of the bag when the disc is rotated and some blood may smear onto the bag thereby exposing the medical technician to possible contact. Furthermore, the disc is sometimes difficult to rotate into the bag and since a disc shape is used, blotter paper is wasted. Also, proper use of this second type timer arrangement requires that care be taken in opening the bag properly. If the bag is destroyed during opening, it is not available to provide a shield or protection for the technician.
The present invention is intended to minimize a medical person's or technician's risk of contact with a patient's blood when the clotting time is measured as well as to present several other improvements over prior art coagulation timers.